debian man page for xdf_add_channel

XDF_ADD_CHANNEL(3)					     xdffileio library manual						XDF_ADD_CHANNEL(3)

NAME
       xdf_add_channel - Appends a channel to a XDF file

SYNOPSIS
       #include <xdfio.h>

       struct xdfch* xdf_add_channel(struct xdf* xdf, const char* label);

DESCRIPTION
       xdf_add_channel()  appends  a  channel to the file referenced by the handle xdf. The new channel is initialized with the label argument (if
       not NULL) and with the default channel values set in the XDF file, i.e. those set using channel	configuration  fields  in  xdf_set_conf(3)
       (See the related manpage).

       If  the call to xdf_add_channel(3) is successful, the default offset value (the field referenced by XDF_CF_ARROFFSET) is incremented by the
       size of the current default stored type (field referenced by XDF_CF_STOTYPE). As a consequence, if the  channel	default  values  have  not
       changed in-between, the next call to xdf_add_channel() will create a channel whose location is the array will be next to the previous one.

       This type of initialization allows the user to add channels without having to specifically pack them: this is achieved by default.

RETURN VALUE
       xdf_add_channel()  returns  the handle to newly created channel descriptor in case of success. Otherwise NULL is returned  and errno is set
       appropriately.

ERRORS
       EINVAL xdf is NULL.

       ENOMEM The system is unable to allocate resources.

       EPERM  the file referenced by xdf has been opened with the mode XDF_READ

SEE ALSO
       xdf_copy_chconf(3), xdf_set_conf(3), xdf_set_chconf(3)

EPFL
								       2010							XDF_ADD_CHANNEL(3)